In a system for testing a terminal antenna, the Theta angle of a rotating table for testing needs to change from 0° to 180° at a step size of 30° (6 steps in total); and the Phi angle of the rotating table needs to change from 0° to 360° at a step size of 30° (12 steps in total). Furthermore, a horizontal polarization direction and a vertical polarization direction are used for a measuring antenna in the standard darkroom, so the total number of testing points are 6*12*2=144.
At each testing point, the testing system gradually decreases the transmitting power of the base station simulator, and then transmits data packets having a fixed length but random contents. After receiving these data packets, the terminal transmits these data packets back to a base station simulator via a transmitting path. The base station simulator compares each bit of the data packets that are transmitted with the data packets that are received so as to calculate a bit error rate (BER) until the BER exceeds a standard threshold. Then, the transmitting power of the base station simulator when the BER exceeds the standard threshold is just the Effective Isotropic Sensitivity (EIS) of the current testing point. According to the 3GPP (The 3rd Generation Partnership Project) standard, for example, the BER standard threshold is 2.44% for GSM (Global System of Mobile communication) and 0.1% for WCDMA (Wideband Code Division Multiple Access).
After the EIS of each of the testing points has been obtained, the path loss (which is a fixed deviation value for a fixed frequency point and a fixed polarization direction of the measuring antenna in the darkroom) in the darkroom is compensated for the EISs. Then, an integration operation is made according to a formula to obtain the final Total Isotropic Sensitivity (TIS).
Because the same operations are executed for each of the testing points, the time consumed in this step determines the final testing time of the whole system. Taking a standard WCDMA TIS test as an example, one BER test has to use 41 data blocks and 82 WCDMA data frames, and takes 82*10 ms=0.82 s. Averagely, 20 searches have to be made for one point, which takes 16.4 s. Therefore, a conventional 3-channel WCDMA TIS needs to take a time of about 16.4*144*3=118 minutes. Accordingly, the EIS searching time in the system for testing a terminal antenna of the prior art is relatively long, which leads to a low testing efficiency.